Disinfection Byproducts in Drinking Water and Human Health

Dave ReckhowUniversity of Massachusetts - Amherst

2009 GRC onWater Disinfection By-Products

Outline

DBP Discovery– Complementary approaches

What’s new?– Iodo compounds– N-DBPS

Reactivity of Specific Nitrogenous Constituents– Amino Acids– Amines, Purines & Pyrimidines– Others

What next?Initial products & End products

Focus on reactions with free chlorine, including comments on other disinfectants

3

John #1: Dr. John Snow

Cholera– First emerged

in early 1800s– 1852-1860: The third cholera pandemic

Snow showed the role of water in disease transmission

– London’s Broad Street pump (Broadwick St) Miasma theory was discredited, but it took

decades to fully put it to rest

1813-1858

2007

4 Picadilly Circus

Soho, Westminster

John #2: Dr. John L. Leal

5

Jersey City’s Boonton Reservoir Leal experimented with chlorine,

its effectiveness and production– George Johnson & George Fuller worked with Leal

and designed the system (1908)

“Full-scale and continuous implementation of disinfection for the first time in Jersey City, NJ ignited a disinfection revolution in the United States that reverberated around the world”

M.J. McGuire, JAWWA 98(3)123

1858-1914

Leal on chlorine

“the practical application of the use of bleach (chlorine) for the disinfection of water supplies seems to me to be a great advance in the science of water purification. It is so cheap, so easy and quick of application, so certain in its results, and so safe, that it seems to me to cover a broader field than does any other system of water purification yet used.”– John L. Leal, 1909

6

7

Chlorination

1-2 punch of filtration & chlorination

Melosi, 2000, The Sanitary City, John Hopkins Press

Greenberg, 1980, Water Chlorination, Env. Impact & Health Eff., Vol 3, pg.3, Ann Arbor Sci.

US Death Rates for Typhoid Fever

John #3: Johannes J. Rook

Short Biography– Education

PhD in Biochemistry: 1949– Work experience

Technological Univ., Delft (~‘49-’54)– Laboratory for Microbiology

Lundbeck Pharmaceuticals in Copenhagen, (~’55-?)

Noury Citric acid Factory (in Holland)

Amstel Brewery Rotterdam Water Works by 1963,

chief chemist (1964-1984). 1984-1986; Visiting Researcher at

Lyonnaise des Eaux, Le Pecq.

– Early Research 1955, Microbiological

Deterioration of Vulcanized Rubber

– Applied Micro. 1964, secured funds for a

GC at Rotterdam– Carlo Erba with gas sample

loop8

9

John Rook & DBPs

Major Contributions– Brought headspace analysis

from the beer industry to drinking water

T&O problems– Found trihalomethanes (THMs)

in finished water Carcinogens !?!

– Published in Dutch journal H2O, Aug 19, 1972 issue

– Deduced that they were formed as byproducts of chlorination

– Proposed chemical pathways

Rook, 1974, Water Treat. & Exam., 23:234

Reactions with Disinfectants: Chlorine

10

HOCl + natural organics (NOM)

Oxidized NOMand inorganic chloride

• Aldehydes

Chlorinated Organics• TOX• THMs• HAAs

Cl

ClCl C H

Br

ClCl C H

Br

ClBr C H

Br

BrBr C H

Chloroform Bromodichloromethane ChlorodibromomethaneBromoform

The THMs

The Precursors!

The Haloacetic Acids

11

HAA5 & HAA6 include the two monohaloacetic acids (MCAA & MBAA) plus– One of the trihaloacetic acids:

– And 2 or 3 of thedihaloacetic acids

Cl

ClCl C COOH

Br

ClCl C COOH

Br

ClBr C COOH

Br

BrBr C COOH

Trichloroacetic Bromodichloroacetic Chlorodibromoacetic TribromoaceticAcid Acid Acid Acid

(TCAA)Cl

ClH C COOH

Br

ClC COOH

Br

BrH C COOH

Dichloroacetic Bromochloroacetic DibromoaceticAcid Acid Acid

(DCAA)

H

HAA6 only

11

Haloacetonitriles

12

Others that are commonly measured, but not regulated include the:– Dihalo-

acetonitriles

– Trihaloacetonitriles

Cl

ClH C C

Br

ClC

Br

BrH C

Dichloroacetonitrile BromochloroacetonitrileDibromoacetonitrile

(DCAN)

HN C N C N

(BCAN) (DBAN)Cl

ClCl C C

Trichloroacetonitrile

(TCAN)

N

12

Halopropanones

13

As well as the:– dihalopropanones

– trihalopropanonesCl

ClCl C C

Br

ClCl C

1,1,1-Trichloropropanone

(TCP)

O H

HC H C

O H

HC H

1,1,1-Bromodichloropropanone

etc.

Cl

ClH C C

1,1-Dichloropropanone

(DCP)

O H

HC H etc.

13

14

DBPs: Formation in Plant

Dist.Sys.

Cl2 Coagulant Cl2 NH3

SettlingFiltration

020406080

100120140160

DB

Ps (u

g/L

)

PrecursorsDBPs

NitrosaminesTrihalomethanesHaloacetic Acids

Dave Reckhow, UMass-Amherst

15

Epidemiology

Bladder Cancer– DBPs linked to 9,300 US cases every year

Other Cancers– Rectal, colon

Reproductive & developmental effects– Neural tube defects– Miscarriages & Low birth weight– Cleft palate

Other– Kidney & spleen disorders– Immune system problems, neurotoxic effects

137,000 at risk in US?

16

National Distribution 241,000,000 people in US are served by

PWSs that apply a disinfectant

Gray et al., 2001 [Consider the Source, Environmental Working Group report]

High THMs are levels of at least 80 ppb over a 3 month average

Hunting for the bad DBPs

Observational/empirical– Multifaceted analysis of treated

waters– Companion toxicity testing

Deductive/theoretical– Postulate DBPs from known NOM

substructures– Exploit Structure-toxicity models

Fewer Constraints

but High Risk

Proven Approach but

Labor intensive

Also allows us to probe NOM contributions to regulated DBPs

The DBP Iceberg

HalogenatedCompounds Non-halogenated

Compounds

ICR Compounds

50 MWDSC DBPs

~700 Known DBPs

THMs, THAAs

DHAAs

Stuart Krasner

Susan Richardson

19

Total Organic Halogen

Standard Methods; USEPA Method #1650 Activated Carbon Adsorption & Pyrolysis &

Microcoulometric Detection of halide Extended Method for TOCl, TOBr, TOI

Trap gases & ion chromatography– (e.g., Hua & Reckhow, 2008)

Pyrolysis OvenMicrocoulometric

Cell

GAC Adsorption

The TOX Pie

THMs20% Haloacetonitriles

2%Chloral Hydrate

1%

HAA510%

Bromochloroacetic Acid3%

Halonitro-methanesHaloketones

Unknown or-ganic Halogen

63%

Data from the Mills Plant (CA) August 1997 (courtesy of Stuart Krasner)

TOX Distribution of Newport News Water

Cl2 (543 g/L)

THM27.6%

CP0.1%

HK1.0%

HAN1.1%UTOX

54.9%HAA

15.4%

O3/Cl2 (395 g/L)

HAA14.4%

UTOX56.6%

HAN0.6%

HK2.3%CP

0.8%

THM25.2%

NH2Cl (66 g/L)

HAA15.4%

UTOX80.2%

HAN0.3%

HK1.8%CP

0.2%

THM2.1%

O3/NH2Cl (56 g/L)

HAA11.2%

UTOX84.0%

HAN0.2%

HK2.2%

CP0.4%

THM2.0%

ClO2 (39 g/L)THM1.8%

CP0.0%

HK0.4%

HAN0.2%

UTOX80.3%

HAA17.3%

Hua & Reckhow, 2007

MW Distribution of Unknown TOX

O3/NH2Cl O3/NH2Cl O3/ClO2 NH2Cl Cl2 Cl2

A B C D E F

Perc

enta

ge(%

)

0

20

40

60

80

100

MW>10K3K<MW<10K

0.5K<MW<3KMW<0.5K

Hua & Reckhow, 2007

Substantial overestimation of MW due to charge effects

Chlorine & Ozone produce iodate

IO3-

Cl2 O3/Cl2 NH2Cl O3/NH2Cl ClO2

I-TH

M (

g/L)

0

10

20

30

40CHCl2ICHClI2CHBrClICHBr2ICHBrI2CHI3

IO3- (

g/L)

0

100

200

300

400

Cambridge MA Water, DOC: 4.2 mg/L, I: 200 g/L Hua & Reckhow, 2007

Iodinated TOX (TOI)C

once

ntra

tion

(g

Cl/L

)

0

100

200

300

400

500TOClTOI

O3 Cl2 O3/Cl2 NH2Cl O3/NH2Cl ClO2

Cambridge MA Water, DOC: 4.2 mg/L, I: 200 g/L

TOI : NH2Cl > ClO2 > Cl2 > O3

Hua & Reckhow, 2007

2D Graph 1

Unknown TOX (g/L)

0 100 200 300 400

TTH

M ( g

/L)

0

20

40

60

80

100

120

140

Unk-TOX vs TTHMc

Regulated DBP as surrogates

EPA’s ICR Database

Organic Chloramines

Stable N-chloroaldimine from amino acids– Pathway favored at lower pHs

Half-life of 35-60 hrs @pH 7-8

Conyers & Scully, 1993 [ES&T 27:261]

Boning LiuPhD student

TOX pie revised

THMs20% Haloacetonitriles

2%Chloral Hydrate

1%

HAA510%

Bromochloroacetic Acid3%

Halonitro-methanesHaloketones

Unknown or-ganic Halogen

63%

Organic Chloramines

Median C/N ratio (15)

5.0

TONXN

2.0

TONXN

28

Source: Who is really responsible?

or

29

Watershed Origins

Aquifer

Lake

Sediment & Gravel in Lake Bed

Algae

30

Leaching Experiments

WhitePine

RedMaple

WhiteOak

Darleen Bryan’s study

31

Algae as THM Precursors From: Plummer & Edzwald, 2001

– [ES&T:35:3661]

Scenedesmus quadricaudaCyclotella sp.~25% from EOM

pH 7, 20-24ºC, chlorine excess

Algae

2D Graph 1

Unknown TOX (g/L)

0 100 200 300 400

TTH

M ( g

/L)

0

20

40

60

80

100

120

140

Unk-TOX vs TTHMc

Regulated DBP as surrogates

EPA’s ICR Database

Watershed Origins

33

Aquifer

Lake

Upper Soil Horizon

Lower Soil Horizon

Sediment & Gravel in Lake Bed

Litter Layer

Algae

33

Plant biopolymers

Cellulose Lignin

– Phenyl-propane units

– Cross-linked– Radical

polymerization– Ill defined

structure Hemicellulose Terpeniods Proteins

Lignin Monomers

Aromatic structures

from CuO degradation

– Syringyl– Vanillyl– Cinnamyl

COOH

OH

4-Hydroxy-benzoic acid

COOH

OH

Vanillic acid

CHO

OH

4-Hydroxy-benzaldehyde

COOH

OH

CH3O OCH3

Syringic acid

CHO

OH

Vanillin

CO

OH

CH3

4-Hydroxy-acetophenone

CHO

OH

CH3O OCH3

Syringaldehyde

CO

OH

CH3

OCH3

COOH

OH

COOH

OHOH

CH3O OCH3

Acetovanilione

4-Hydroxy-cinnamic acid

CO

CH3

Acetosyringone

OCH3

Ferulic acid

OCH3

OCH3

Chl

orin

e D

eman

d(M

/M-c

ompo

und)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

TOX

Formation

(M-C

l/M-com

pound)0.0

0.5

1.0

1.5

2.0

Cl2 Demand TOX Unkn TOX

4-hydroxybenzoic acid

4-hydroxybenzaldehyde

4-hydroxyacetophenone

TOXSpeciation

TTHMTHAADHAADHANUnkn TOX

COOH

OH

CHO

OH

CO

OH

CH3

4-hydroxy benzenes

Among the most reactive structures tested

Alkali CuO oxidation Method

Oven method: Hedges and Ertel (1982)– 1g CuO, 25-100 mg FAS, 7

mL NaOH– 170 oC in oven for 3 hours

Microwave method: Goni (1998)– 500 mg CuO, 50 mg FAS, 15

ml 2N NaOH– 150 oC in microwave for 90

min

Mining the literature to postulate “new” DBPs

Chlorination of p-hydroxybenzoic acid based on Larson and Rockwell (1979). “A” represents electrophilic aromatic substitution, “B” is oxidative decarboxylation

OH

HO O

O

HO O

HO

HO O

HO

HO O

H

O

HO O

H

Cl

H

OH

HO O

Cl

O

O O

H

ClH

OH

Cl

AB

2

1 OH

HO O

ClCl

OH

Cl

Cl

OH

Cl

ClCl

3

4 5

A

B B

A A

Chloro-substitution of the benzene ring and followed decarboxylation:

Environmental Science & Technology 1979, 13, 325

Haloquinones are likely intermediates

PAHA II

Fill in missing steps by analogy– Halohydroxy-

dienoic acids– TCAA

O

Cl

ClCl

5O

Cl

ClCl

H

ClOH

Cl

C CHO

Cl3C HC

Cl

CC O

O

Cl

H

OH Cl

C CH

Cl3C HC

Cl

CC O

O

Cl

HHO ClH Cl

C CHO

Cl3C HC

Cl

CC O

O

Cl

H

HCl

C CHO

Cl3C HC

Cl

CC O

O

Cl

H

C CHO

Cl3C HC

Cl

CC O

O

Cl

H

HO

Cl

HO Cl OH Cl

O Cl

COOH

C

Cl3C

HCCl

CC O

O

Cl

H

Cl

Cl

H2O

H

7

6

Nitrogenous Biopolymers Why focus on these?

– Nitrogenous organics are generally quite reactive– N-DBP formation can be enhanced by chloramination– Some evidence that they are major contributors to

adverse human health effects of DBPs– Relatively little is known about N-DBPs

Key suspects– Amino Acids & Proteins– Nucleic Acids, Pyrimidines & Purines– Others (e.g., porphyrins)

Percentile

0 10 20 30 40 50 60 70 80 90 100

DO

C/D

ON

(mg-

C/m

g-N

)

0

10

20

30

40

50

60

27

15

8.2

Organic Nitrogen Abundance

Ratio to carbon– Redrawn from Westerhoff & Mash, 2002

N-DBPs we know about: end products

Certain to come from N-organics when using free chlorine

Major types:– Cyanogen Halides – Haloacetonitriles– Halonitromethanes

Cl

ClH C C

Br

ClC

Br

BrH C

Dichloroacetonitrile BromochloroacetonitrileDibromoacetonitrile

(DCAN)

HN C N C N

(BCAN) (DBAN)Cl

ClCl C C

Trichloroacetonitrile

(TCAN)

N

Special focus on these compounds because of large data set

Cl

ClCl C NO

Chloropicrin

(CHP)

2

CNCl & CNBr

9 species

Occurrence

DHANs are typically 10% of THM level

Krasner et al., 2002 [WQTC]– 12 plant survey

ICR (mean for all)– HAN4: 2.7 µg/L– CP: <0.5 µg/L– CNCl: 2.1 µg/L

Single Cell Gel Electrophoresis Genotoxicity PotencyLog Molar Concentration (4 h Exposure)

10-6 10-5 10-4 10-3 10-2

IAA

BA

A

CA

A

DIA

A

TBA

A

DB

AA3,

3-D

ibro

mo-

4-ox

open

tano

ic A

cid

2-B

rom

obut

ened

ioic

Aci

d

2-Io

do-3

-bro

mop

rope

noic

Aci

d2,

3-D

ibro

mop

rope

noic

Aci

d

DB

NM

BD

CN

MTB

NM

TCN

M

BN

M

BC

NM

DB

CN

M

DC

NM

CN

M

Bro

moa

ceta

mid

e

Dib

rom

oace

tam

ide

Trib

rom

opyr

role

MX

Bro

mat

e

EMS

+Con

trol

Haloacetic Acids

Halo Acids

Haloacetamides

Halonitromethanes

Other DBPs

DBP Chemical Class

Not Genotoxic: DCAA, TCAA, BDCAA, Dichloroacetamide, 3,3-Dibromopropenoic Acid, 3-Iodo-3-bromopropenoic Acid, 2,3,3,Tribromopropenoic Acid July 2006

Chl

oroa

ceta

mid

e

Trih

loro

acet

amid

e

Iodo

acet

amid

e

Haloacetonitriles Bro

moa

ceto

nitri

le

Dib

rom

oace

toni

trile

Bro

moc

hlor

oace

toni

trile

Chl

oroa

ceto

nitri

le

3,3-

Bro

moc

hlor

o-4-

oxop

enta

noic

Aci

d

Iodo

acet

onitr

ile

Tric

hlor

oace

toni

trile

Dic

hlor

oace

toni

trile

BIA

A

CD

BA

A

BC

AA

Work of Michael Plewa

44

Genotoxicity

>100

0

>100

-100

0

>10-

100

>1-1

0

>0.1

-1

>0.0

1-1

Distribution of estimated chronic LOAELs, mg/kg day-1

0

100

200

Numb

er o

f hal

ogen

ated

DBP

s

0

5

10

15

Numb

er o

f hal

onitr

iles

Al l Ha l o DBPs

Ha l o n i t ri l e s

Lowest Observed Adverse Effect Level– AWWARF report by Bull et al., 2007

Quantitative Structure-Toxicity Models

DHAN

Chemical Degradation in Distribution Systems

Accelerated by chlorine and base

C NC

H

Cl

Cl

CC

H

Cl

Cl

O

OH

CC

H

Cl

Cl

N

OH

CC

H

Cl

Cl

NH

OH

CC

H

Cl

Cl

N

OCl

CC

H

Cl

Cl

NH2

O

CC

H

Cl

Cl

NHCl

O

H2O

NHCl2NH3

Cl(+II)

S (+IV)

CC

H

Cl

Cl

NCl

O

CC

H

Cl

Cl

NHCl

OCl

OH

CC

H

Cl

Cl

NH2

OH

O

pKa = 3.7

H2O

fast fast

fast

fast

fast

k2

k1

k4

k1-2k1-1

DCAN

DCAD

DCAA

HOCl

OClOH

OH

OH

N-Cl-DCAD

N-Cl-DCADanion

Hydrolysis and oxidation

Proposed Rate Law for DCAN

k1 = 1.78 x10-7 ±0.35 x10-7 (s-1)k2 = 3.42 ±0.31 (M-1s-1)k3 = 1.30 x 10-1 ±0.08 x 10-1 (M-1s-1)

dCdt

k k OH k Cl I C { [ ] [ ( )]}1 2 3

DCAN half-life based on pH & HOCl

pH6 7 8 9 10 11

Chl

orin

e R

esid

ual (

mg/

L)

0.1

1

10

100

DCAN Halflife

OH-

OCl-

H2O

10 Minutes

1 Hour8 Hours

1 Day

3 Days

1 Week

3 Weeks

At 20 C From Reckhow,

Platt, MacNeill & McClellan, 2001

– Aqua 50:1:1-13 Degradation in DS

observed to increase with increasing pH

– ICR data: Obolensky & Frey, 2002

DCAD

Formed from degradation of DCAN

Readily halogenated– Only exists as

N-Cl-DCAD?

C NC

H

Cl

Cl

CC

H

Cl

Cl

O

OH

CC

H

Cl

Cl

N

OH

CC

H

Cl

Cl

NH

OH

CC

H

Cl

Cl

N

OCl

CC

H

Cl

Cl

NH2

O

CC

H

Cl

Cl

NHCl

O

H2O

NHCl2NH3

Cl(+II)

S (+IV)

CC

H

Cl

Cl

NCl

O

CC

H

Cl

Cl

NHCl

OCl

OH

CC

H

Cl

Cl

NH2

OH

O

pKa = 3.7

H2O

fast fast

fast

fast

fast

k2

k1

k4

k1-2k1-1

DCAN

DCAD

DCAA

HOCl

OClOH

OH

OH

N-Cl-DCAD

N-Cl-DCADanion

6 7 8 9 10 11pH

6 7 8 9 10 11

Chl

orin

e R

esid

ual (

mg/

L)

0.1

1

10

100

DCAD Halflife

3 Weeks

1 Hour

8 Hours

1 Day

3 Days

1 Week

10 Minutes

OH-

HOCl

3 Weeks

1 Hour

8 Hours

1 Day

3 Days

1 WeekReducingConditions

DCAD Stability

Percentile

0 10 20 30 40 50 60 70 80 90 100

DO

C/D

ON

(mg-

C/m

g-N

)

0

10

20

30

40

50

60

27

15

8.2

Organic Nitrogen Abundance

Ratio to carbon– Redrawn from Westerhoff & Mash, 2002

Organic-N: Types & Abundance

Amino Abun-Acid dance

Glycine 11.7%Alanine 11.7%Valine 5.2%Isoleucine 4.4%Leucine 5.6%Serine 10.8%Threonine 7.0%Methionine 1.0%Aspartic Acid 10.2%Glutamic Acid 10.0%Lysine 1.6%Ornithine 2.0%Arginine 7.4%Histidine 2.5%Asparagine 0.4%Glutamine 0.5%Tryptophan 2.5%Phenylalanine 3.4%Tryrosine 2.2%SUM 100.0%

52

[1] Based on an average of: Isle Bay water (Yamashita & Tanoue, 2003), Lake Biwa (Wu et al., 2003), and water column values, summer, from Thomas, 1997

Classification 50%ile 90%ile 99%ileDON 350 800 2000Free AA 20 50 200Combined AA 40 100 400Nucleic acids 20 50 200Amino Sugars 40 100 400Humic-N 25 200 1000

Estimates in µg-N/L

From: Bull et al., 2006

N C

R1

H

R4

R3R2

N C

R1

X

R4

R3R2

N C

X

X

R4

R3R2

R1=H

X+

CO

R4

R3

R1NH2

R2=H or COOH

CN R3

R4=H

HX (CO2)

R2=H or COOH

CNR3

X R4

I II

III IV

V

CNR3

R1 R4

VI

Nu

NH2X

X+

Nu

R1=H

X+

Nu

HX

HX (CO2)

MonohalaminePathway

DihalaminePathway

Reaction pathways

General scheme for carbonyl and cyano formation from chlorination of amines, amino acids & related compounds– (adapted from Nweke

and Scully, 1989, and Armesto et al., 1998).

Many N-halo products

54

Total Organic Halogen

Standard Methods; USEPA Method #1650 Activated Carbon Adsorption & Pyrolysis &

Microcoulometric Detection of halide Extended Method for TOCl, TOBr, TOI

Trap gases & ion chromatography– (e.g., Hua & Reckhow, 2008)

Pyrolysis OvenMicrocoulometric

Cell

GAC Adsorption

TOX pie revised

THMs20% Haloacetonitriles

2%Chloral Hydrate

1%

HAA510%

Bromochloroacetic Acid3%

Halonitro-methanesHaloketones

Unknown or-ganic Halogen

63%

N-Halo Organics

Median C/N ratio (15)

5.0

TONXN

2.0

TONXN

Amino Acids

Free, combined & “humic”

Amino Acids: Chlorine Demand

2D Graph 1

Precursor

Chl

orin

e D

eman

d (m

g/m

g-C

)

0

2

4

6

8

10

12

AquaticNOM

Fractions

SelectedAmino Acids

More reactive than most NOM

From: “DBP Formation from Amino Acids and Proteins in NOM”, Kim & Reckhow, in preparation

Classic Mechanism

2 Pathways– Formation of nitriles

with excess chlorine– Formation of

aldehydes with under-chlorination

Aldehyde

Froese, Kenneth L., Wolanski, Alina, and Hrudey, Steve E. “Factors Governing Odorous Aldehyde Formation as Disinfection By-Products in Drinking Water”. Water Research 33[6], 1355-1364. 1999.

Isoleucine

Nitrile

Dihaloacetic Acid

2D Graph 1

Precursor

Dih

aloa

cetic

Aci

d Fo

rmat

ion

( g/m

g-C

)

05

1015202530354045505560

100150200250300350400

AquaticNOM

Fractions

Selected Amino Acids

387

89115

Aspartic acid

Histidine

Asparagine

Dihaloacetonitriles

Aspartic acid

Histidine

2D Graph 1

Precursor

Dih

aloa

ceto

nitri

le F

orm

atio

n ( g

/mg-

C)

0123456789

101112131415

50100150200250

AquaticNOM

Fractions

Selected Amino Acids

255

85

Early Recognition of DHAN pathway– From Trehy, 1980 (MS

Thesis)

Aspartic Acid

Phenylalanine

Stable N-chloroaldimine– Pathway favored at lower pHs

Half-life of 35-60 hrs @pH 7-8

Conyers & Scully, 1993 [ES&T 27:261]

Asparagine

Oxidant Residuals and CNCl– 0.036 mM Asparagine, pH 7, 30 min– Shang, Gong & Blatchley, 2000

(Shang et al., 2000)

FreeTriDiMono

Res

idua

l Chl

orin

e (m

g/L

)

Cya

noge

n C

hlor

ide

(ug/

L)

Asparagine

NH2

CH

C

H2C

HO O

C

H2N

O

NCH

C

H2C

O O

C

H2N

O

Cl

Cl

H

NCHH2CC

N

O Cl

H

H

NCH2CC

N

O

H

H

Cl

O

HO

H

NCH2CC

N

O

H

H

H

O

Cl

NCH2CN

H

H

HCOOH

NCH2CN

Cl

Cl

N,N-Dichloroaminoacetonitrile

NCCH

N

Cl

N-Chloroiminoacetonitrile

HCl

2HOCl

OCl-

NCHH2CC

N

O Cl

ClHOCl

N-Chloroimino-N-Chloroacetamide

CO2

HCl

HCl

Aminoacetonitrile

H+

Proposed degradation pathway– Showing major,

non-trivial “stable” products

Polypeptide linkages

Compound

Asp-Asp-Asp-Asp

L-Aspartyl-L-PhenylalanineAlbumin

Hemoglobin

LysozymeInsulin

Cl 2 D

eman

d (m

g/m

g-N

)

0

2

4

6

8

10

12

14

16

18

20

22

24

Cl 2

Dem

and

(M/M

-N)

0

1

2

3

4

Measured Cal w/ amide Cal w/o amide

Amide nitrogen thought to react slowly– About 5% under

conditions used Based on Jensen

et al., 1999

More reactive than expected– Demands calculated

from component AAs both with and without amide reactivity

4 2 815 736 192 65

# of AAs

Proteins vs Amino Acids Cont

Comparison to constituent free AAs– same dihalo; more trihalo– Somewhat more TOX & UTOX

Lysozyme

DBP

TTHM TCAA DCAA TOX UnKn TOX

DB

P F

orm

atio

n (

g/m

g-N

)

0255075

100125150175200225250275300325350

400

500

600

700

DB

P F

orm

atio

n (

g/m

g-C

)

0102030405060708090100110120

150175200225250

Observed Predicted

Insulin

DBP

TTHM TCAA DCAA TOX UnKn TOX

DB

P F

orm

atio

n (

g/m

g-N

)

0102030405060708090

100

200

300

400

500

DB

P F

orm

atio

n (

g/m

g-C

)

0

5

10

15

20

25

50

75

100

125

150

Observed Predicted

Aromatic Amines

When R is electron withdrawing– Otherwise ring

halogenation precedes N-chlorination

– With some R both can occur

– May also occur with R in ortho position

NR

H

H

NR

Cl

Cl

2HOCl

NR Cl

O

H

O

Cl-

H

N

Cl

O

RH

N-chloro-p-benzoquinoneimine

OO

HOClOH-

Quite stableFrom study of Sufamethoxazole

(Dodd & Huang, 2004)

Some New DBPs

Compound 50%ile 90%ile 99%ileN-Chloroiminoacetonitrile 0.3 0.6 2.5

N-N-Dichloroaminoacetonitrile 0.6 1.4 5.5

N-Chlorophenylacetaldimine 5.5 13 53

Concentrations in µg/L

Finished Drinking Water Concentrations

Assumptions– N-Chloroiminoacetonitrile and N-N-Dichloroaminoacetonitrile were derived

only from Asparagine at yields of 40% and 60% respectively– N-Chlorophenylacetaldimine was only from phenylalanine at a yield of 50%– Proteins yielded 50% of component AA byproducts

Summary

A broad range of nitrogenous organic compounds in natural waters are reactive with chlorine and produce both regulated and non-regulated DBPs– Amino acids are generally reactive– Proteins may be more important than previously thought– Nucleic acids (bases) are all quite reactive

N-chloro DBPs may be important – Reactive; could be quite prevalent; maybe toxic?– Causes “hidden TOX”

Chloramination may not be effective at reducing these byproducts Other DBPs that may be of concern include

– Haloquinones– Halonitriles– Nitrosamines– Iodo compounds

Acknowledgements

Richard Bull UMass Researchers

– Guanghui Hua & Boning Liu– Junsung Kim & Hans Mentzen– Andrew MacNeill

Sponsors– AWWA Research Foundation (now WRF)

Project #2867; Report #91135– Others: NSF, EPA

The End

TD50’s of carcinogenic nitroso compounds vs. NOAEL Halo DBPs

>100

0

>100

-100

0

>10-

100

>1-1

0

>0.1

-1

>0.0

1-1

TD50 or chronic LOAEL, mg/kg day -1

0

100

200

Numb

er o

f hal

ogen

ated

DBP

s

0

20

40

60

Nitro

so c

arci

noge

ns

Al l h a l o DBPsNi t ro s o c mp d s

Research needs

Group Example Occurrence

Toxicology

Haloquinones 2,6-dichloro-3-methyl-1,2-benzoquinone (DMBQ)

1 2

Organic N-haloamines

Prioritize on range of stabilities and mutagenic activity

2 1

Alkaloidal nitrosamines

N-nitrosonornicotine 1-N-oxide

1 2

Cyclopentenoic acids & MX-related

3,5-dichloro—1-hydroxy-4-ketocyclopent-2-enoic acidCMCF

1

2

2

1Halonitriles 2,3-Dichloropropenal (Carc)

2,3-dibromopropionitrile (DT)

1 1

Conclusions: from QSTR

74

Known vs. Unknown Cl2 BPs

Reaction Time

Chlorination of Aquatic NOM(after Reckhow & Singer, 1984)

Time (hrs)

0 20 40 60 80 100 120 140 160

DB

P C

once

ntra

tion

( g

/L)

0

100

200

300

400

500

Oxi

datio

n an

d U

nkno

wn

TOX

( g

/L)

0

100

200

300

400

500

600

700

800

900

Unknown TOX

0.1 x Oxidation

THAA+THM

20 mg/L chlorine dosepH 7.020oC

DHAA

75

Known vs. Unknown Cl2 BPs Dose

effects

Chlorine Dose (mg/L)

10 100

Oxi

datio

n an

d U

nkno

wn

TOX

( g

/L)

0

200

400

600

800

1000

1200

DB

P C

once

ntra

tion

( g

/L)

0

50

100

150

200

250

300

350

400

450

500

550

600

THAA + THM

0.1 x Oxidation

Unknown TOX

DHAA

76

Known vs. Unknown Cl2 BPs pH effects

pH

2 3 4 5 6 7 8 9 10 11 12

Oxi

datio

n an

d U

nkno

wn

TOX

( g

/L)

0

200

400

600

800

1000

1200

DB

P C

once

ntra

tion

( g

/L)

0

50

100

150

200

250

300

350

400

THAA & THM

0.1 x Oxidation

Unknown TOX

DHAA

Proteins & Polypeptides Ratio of observed to predicted

Amide linkages cause:– small decrease in chlorine demand– Mixed affect on TOX– Higher trihalo DBPs (THM, TCAA)– No DCAN

Cl2 Demand TOX THM TCAA DCAA

Unkn TOX

Albumin 0.73 1.06 2.83 2.17 0.66 1.02Hemoglobin 0.91 0.90 4.49 3.20 0.61 0.52Lysozyme 0.82 1.70 2.40 3.51 0.99 1.73Insulin 0.85 1.66 1.40 1.63 1.05 1.98

Conclusions: AAs & Proteins Aspartic acid alone may be responsible for a substantial

amount of the DHANs in treated drinking waters Proteins are surprisingly reactive despite “recalcitrant”

amide nitrogens Side chains are probably the site of most attack Tendency to form more trihalo DBPs as compared to free

amino acids, but almost no HANs Similar amount of unknown TOX is formed despite

relatively unreactive amide nitrogen Need to identify more “UTOX” N-chloro compounds should be investigated

Glycine

Na & Olson, 2006

Proposed Pathways of N,N-Dichloroglycine Decay

Chlorination of Tryptophan– From Trehy, 1980 (MS

Thesis) Similar mechanism for

Tyrosine– Trehy et al., 1986

ES&T 20:1117

Tryptophan

M/M Prediction ObservationCl2 Dem 4 15

DHAN 1 0.01-0.02

TOX 2 1.9

THM 0 0.16

THAA 0 0.11

DHAA 0 0.06

UTOX 0 0.85

Chl

orin

e D

eman

d(M

/M-c

ompo

und)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

TOX

Formation

(M-C

l/M-com

pound)

0.0

0.5

1.0

1.5

2.0Cl2 Demand TOX Unkn TOX

Anthranilicacid

3 Amino-benzoic acid

4 Amino-benzoic acid

2 Amino-phenol

TOXSpeciation

TTHMTHAADHAADHANUnkn TOX

Continued Reaction

From Model compound studies

Conclusions: Amino Acids

All 20 essential amino acids are highly reactive with chlorine

Several react to form substantial amounts of “unknown” organic halide byproducts– Histidine, Asparagine, Tryptophan, Tyrosine, Aspartic Acid

Only Tryptophan and tyrosine produce elevated levels of THMs and THAAs

Aspartic acid produces very large yields of DHANs and DHAAs

Aspartic acid alone is responsible for a substantial amount of the DHANs in treated drinking waters

Conclusions: Proteins Proteins are surprisingly reactive despite “recalcitrant”

amide nitrogens Side chains are probably the site of most attack HANs are not produced by the bound Asp Tendency to form more trihalo DBPs as compared to

free amino acids Similar amount of unknown TOX is formed despite

relatively unreactive amide nitrogen Need to identify more “UTOX”

Acknowledgements Research Support

– American Waterworks Association Research Foundation

– National Science Foundation Many UMass students, post-docs, and

collaborators– Richard Bull– Junsung Kim, Darlene Bryan, Gladys Makdissy,

Cynthia Castellon Many Drinking Water Utilities

Compare with Model Compounds

85THM Precursors (g/mg-C)

0.01 0.1 1 10 100 1000 10000

TriH

AA

Pre

curs

ors

(g/

mg-

C)

0.01

0.1

1

10

100

1000AromaticsNucleic BasesSimple AliphaticsAmino AcidsAmino Sugars

Wide range in reactivity

Balance of formation & degradation

Above pH 7.5– DCAD is formed

faster than it decomposes

Below pH 7.0– DCAD

decomposition is faster

– It is just a transient intermediate; present at some pseudo-steady state concentration

pH6 7 8 9 10 11

Chl

orin

e R

esid

ual (

mg/

L)

0.1

1

10

DCAD Degradation

8 Hours

1 Day

3 Days

1 Week

DCAD formation

NOM Origins: Metabolic Pathways

Pyruvate

Acetate

Water Soluble Acids

Porphyrins

AminoAcids

NucleicAcids

Misc. N & S compounds

ProteinsShikimic Acid

CarbohydratesSaponifiable

Liquids

UnsaponifiableLiquids

Mevalonic acid

Terpenoids

Steroids

Flavonoids

Aromatic Compounds

From: Robinson, 1991Activated non-N precursors

Nitrogenousprecursors

Aromatic Amines

Proposed degradation pathway for 3-amino benzoic acid.

C

NH2

O

OH 1, 2, or 3 chlorinations initially

NH2

Cl

Cl Cl

COOH

NCl2

Cl

NH2

Cl

Cl

COOH

Cl

Cl

OHAnd or chlorination of the amine

OH

NH2

Cl

Cl

COOH

Cl

ClCl2

COOH

Cl

Cl

O

Cl

Cl

COOH

Cl

Cl

Cl

Cl

O

OHOH

OH

Cl

Cl

Cl

Cl

Cl

COOHOHl

Cl

O

COOH

Cl

Cl

O

Cl

Cl

COOH

Cl

Cl

O

Cl

Cl

- NCl2H

Cl

Cl

O

Cl

Cl

OH

O

OH

Cl

Cl

O

Cl

Cl

O

OH

HO

COOH

Cl

Cl

O

Cl

Cl

COOH

Cl

Cl

Cl

Cl

Cl

Cl

COOH

Cl

Cl

O

Cl

Cl

COOH

Cl

Cl

O

Cl

Cl

Cl

Cl

O

Cl

Cl

Cl

HO

HO

HO

Cl

-CO2

O

OH

O

Cl

OH

O

Cl

Cl

ClHOOC

Cl

ClInitial decarboxylation that we would predict for thepara substituted compound is less likly here because the intermediateis not resonance stabilized

Ranges of Org-N by types

Estimates from literature surveys

Classification 50%ile 90%ile 99%ileDON 350 800 2000Free AA 20 50 200Combined AA 40 100 400Nucleic acids 20 50 200Amino Sugars 40 100 400Humic-N 25 200 1000Others

Order of magnitude estimates for organic nitrogen in surface waters(all values in µg-N/L)

Algae are known Precursors

From: Plummer & Edzwald, 2001– [ES&T:35:3661]

Scenedesmus quadricaudaCyclotella sp.~25% from EOM

pH 7, 20-24ºC, chlorine excess

Algae

).,.( 32 CHClgeTHMsNOM Cl

Algal Impacts on Water Supplies

91

ICR Month

0 2 4 6 8 10 12 14 16 18 20

TOC

(mg/

L) o

r SU

VA

(m-1)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Approximate Date

6/1/

1997

7/1/

1997

8/1/

1997

9/1/

1997

10/1

/199

7

11/1

/199

7

12/1

/199

7

1/1/

1998

2/1/

1998

3/1/

1998

4/1/

1998

5/1/

1998

6/1/

1998

7/1/

1998

8/1/

1998

9/1/

1998

10/1

/199

8

11/1

/199

8

12/1

/199

8

1/1/

1999

2/1/

1999

TOC: Kornegay dataSUVA: ICR

TOC: ICR

Lake Lanier WTPGwinnet Co., GA

Influent Water

High photosynthetic

activity

91

Many examples– e.g., Lake

Lanier Source for

Gwinnett Co.’s (GA) Lanier WTP

Often attributed to release of proteinaceous material

2D Graph 1

Precursor

Trih

alom

etha

ne F

orm

atio

n ( g/m

g-C

)

05

10152025303540455055606570

80

100

120

140AquaticNOM

Fractions

SelectedAmino Acids

113

147

Minor except for two– Tryptophan

– Tyrosine

AAs: THM formation

Cyanogen Halides

Cyanogen Chloride

Cyanogen Bromide

dCdt

k OH k OCl C { [ ] [ ]}2 4

dCdt

k OH C 2[ ]

k2 = 3.4 ±0.3 (M-1s-1)

k2 = 3.0 ±0.1 (M-1s-1)k4 = 40 ±6 (M-1s-1)

All at 20oC

COHkkdtdC ][21

112

171

8.2

109.2

sMk

sxk

Pedersen & Mariñas, 2001 COClkOHkk

dtdC ][][ 421

114

112

171

640

2.09.2

109.2

sMk

sMk

sxk

Xie & Reckhow, 1993

Xie & Reckhow, 1993

Roughly in agreement with Na & Olson

Nitrosamines

NDMA: typically formed at greater levels with chloramination than with chlorination– Continues to form across DS?

other nitrosamines (beyond NDMA) have been reported in chloraminated water

Levels and mechanisms– Earlier work: Valentine & Weinberg– New mechanism: Mitch

One possible pathway to NDMA

Role of Dichloramine and oxygen

N

Cl

Cl

H N

CH3

CH3

R N N

H

Cl

CH3

CH3

R ClDichloramine

Dimethyl(xx)amine

Monochloro Unsymmetric Dimethylhydrazine (UDMH-Cl)

N

Cl

Cl

H

O O

PRODUCTS

Nitrosodimethylamine(NDMA)

Oxygen

N N

CH3

CH3

O

From: Walse & Mitch, 2008 [ES&T,

42:4:1032]

96

Unnatural Precursors?

Ranitidine (Zantac)– 63% conversion to NDMA

Schmidt et al., 2006 [WQTC]– Introduced in 1981, largest selling prescription drug by

1988 Stomach ulcers and esophageal reflux

– Mean concentration of 3000 ng/L estimated for raw municipal WW (national average)

Sedlak 2005 AWWARF report– 450 ng/L formation in raw WW expected– Unknowns: how much does this persist in treatment and in

the environment?

Abbreviations– DMD: dimethyldiazene– TMT: tetramethyltetrazene– FMMH: formaldehyde

monomethylhydrazone– FDMH: formaldehyde

dimethylhydrazone– DMC: dimethylcyanamide– DMF: dimethylformamide

From: Mitch & Sedlak, 2002 [ES&T, 36:588]

Many products from UDMH

Reactions with Chlorine

HOCl + natural organics (NOM)

Oxidized NOMand inorganic chloride

• Aldehydes

Chlorinated Organics• TOX• THMs• HAAs

Cl

ClCl C H

Br

ClCl C H

Br

ClBr C H

Br

BrBr C H

Chloroform Bromodichloromethane ChlorodibromomethaneBromoform

The THMs

The Precursors!

An Aquatic Humic “Structure”

COOH

O

COOH

COOH

COOH

HOOC

HOOC

HO

OH

COOH

H3CO

OHHydroxy Acid

AromaticDicarboxylicAcid

AromaticAcid

Aliphatic Acid

AliphaticDicarboxylicAcid

Phenolic-OH

HO

From Thurman, 1985

TOX: Known & Unknown

Trihalomethanes20%

Sum of 5 Haloacetic Acids10%

Bromochloroacetic Acid3%

Unknown Organic Halogen

64%

Chloral Hydrate1%

Haloacetonitriles2%

HaloketonesChloropicrin

Data from the Mills Plant (CA) August 1997 (courtesy of Stuart Krasner)

RegulatedDBPs

But, the Bad Stuff is

probably somewhere

here

N-chloro-organics

Reactions of chlorine with organic amines– Primary amines

– Secondary amines

Inorganic chloramines can transfer their active chlorine in a similar fashion

22 NClRNHClRNHR HOClHOCl

NClRNHR HOCl 22

Degradation of Organic Chloramines

Parent Amine kobs (s-1) t½ (min) Alanine 1.3E-04 86 Glycine 1.4E-06 8400 Histidine 2.7E-04 43 Leucine 1.6E-04 72 Phenylalanine 2.2E-04 52 Serine 2.4E-04 49 Creatinine 3.5E-06 3300 Glycine N acetyl 6.0E-07 19000 Glycine ethyl ester 2.3E-04 50 Glycylglycine 1.0E-05 1100 Sarcosine 5.3E-05 210

103

Known vs. Unknown Cl2 BPs Dose

effects

Chlorine Dose (mg/L)

0 20 40 60 80 100 120 140 160 180 200 220

Oxi

datio

n an

d U

nkno

wn

TOX

( g

/L)

0

200

400

600

800

1000

1200

DB

P C

once

ntra

tion

( g

/L)

0

50

100

150

200

250

300

350

400

450

500

550

600

THAA + THM0.1 x Oxidation

Unknown TOX

DHAA

Vanillic acid Vanillin Aceto vanillione

Chl

orin

e D

eman

d(M

/M-c

ompo

und)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

TOX

Formation

(M-C

l/M-com

pound)0.0

0.5

1.0

1.5

2.0

Cl2 Demand TOX Unkn TOX

TOXSpeciation

TTHMTHAADHAADHANUnkn TOX

COOH

OH

OCH3

CHO

OH

OCH3

CO

OH

CH3

OCH3

Vanillins Similar

patterns

Syringic acid Syring aldehyde Aceto syringone

Chl

orin

e D

eman

d(M

/M-c

ompo

und)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0TO

X Form

ation(M

-Cl/M

-compound)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Cl2 Demand TOX Unkn TOX

TOXSpeciation

TTHMTHAADHAADHANUnkn TOX

COOH

OH

CH3O OCH3

CHO

OH

CH3O OCH3

OH

CH3O OCH3

CO

CH3

Syringyls

No ring-based THMs

Analysis of Lignins & NOM Multiple tests

– Yields (mg/100mg)

Monomer Abbr. Organosolve lignin

Alkali lignin Humic acid Fulvic acid

Vanillic Acid VAD 0.51 1.37 0 0.51 Vanillin VAL 5.57 6.36 0 0 Acetovanillone VON 2.43 2.71 0.37 0.43 Syringic Acid SAD 0.11 <0.1 3.4 4.15 Syringaldehyde SAL 8.59 <0.1 <0.1 <0.1 Acetosyringone SON 6.01 <0.1 1.56 <0.1 p-Coumaric Acid CAD 1.97 <0.1 0 <0.1 Ferulic Acid FAD 6.01 <0.1 1.56 <0.1 p-OH Benzoic Acid PAD <0.1 0.02 0 0.49 p-OH Benzaldehyde PAL 0.68 0.05 0.04 <0.1 p-OH Acetophenone PON 0.65 0.71 0.89 <0.1 Total Lignin Phenols5 26.52 11.22 6.66 5.59 Total Lignin Carbon7 20.15 7.10 4.67 3.13

DBP yields

Lignin acts much like the sum of its monomers

Substantial source of carbonaceous precursors

Mea

sure

d D

BP

yie

ld (

M/m

M C

)

0

2

4

6

8

Mea

sure

d TO

X y

ield

(M

Cl/m

M C

)

0

20

40

60

80

Est

imat

ed D

BP

yie

ld (

M/m

M C

)

0

2

4

6

Oragnosolv lignin Alkali lignin

Est

imat

ed T

OX

yie

ld (

M C

l/mM

C)

0

10

20

30

THMs2XAA3XAATOX Unknown TOX

From: “Analysis of Lignin in NOM Using Alkali CuO Oxidation”, Kim & Reckhow, in preparation

Why N-DBPs?

Nitrogenous organics are generally quite reactive

Can be enhanced by chloramination Some evidence that they are major

contributors to adverse human health effects of DBPs

Very little is known about N-DBPs Analytical chemistry is more complicated

Ranges of Org-N by types

Estimates from literature surveys

Classification 50%ile 90%ile 99%ileDON 350 800 2000Free AA 20 50 200Combined AA 40 100 400Nucleic acids 20 50 200Amino Sugars 40 100 400Humic-N 25 200 1000Others

Order of magnitude estimates for organic nitrogen in surface waters(all values in µg-N/L)

Haloacetamides

Mostly from HANs:

AcidsHaloaceticidesHaloacetamitrilesHaloaceton

N-HalogenatedForms

Free (f)

Combined (c )

Chlorine Sulfite

Total (t)

Measureable by GC

Ultrafiltration of DCAA and TCAA

DCAA TCAA

Con

cent

ratio

n (

g/L)

0

10

20

30

40

50

Raw 10K 3K 0.5K

MW: DCAA, 128.9; TCAA, 163.4Hua & Reckhow, 2007

Halamides

Compounds – Monohaloacetamides

Chloroacetamide, Bromoacetamide– Dihaloacetamides

Dichloroacetamide (DCAD) Bromochloracetamide (BCAD) Dibromoacetamide (DBAD)

– Trihaloacetamides trichloroacetamide & analogues

Chlorination byproducts– Probably a bit less prevalent with chloramines– Pre-oxidation will probably reduce subsequent

formation

Time (hrs)

0 20 40 60 80 100 120

Dic

hlor

oace

toni

trile

(g/

L)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

10 mg/L 5 mg/L 2.5 mg/L

Loss of Residual

Chlorine Dose

Dichloroacetonitrile (DCAN)

Surface WaterChemical Degradation in Distribution Systems

Amino Acids and Proteins

H2C CH

COOH

NH2

HO CH2

CH

NH2

COOH

Tyrosine

Simple Amino Acids– some form THMs and HANs– Highest reactivity for

activated AAs Tyrosine & Tryptophan:

activated aromatic Cysteine: sulfhydryl group

Proteins– many linked AAs; relatively

unreactive polypeptide bonds

– Reactions with proteins occurs most readily on AA side chains

Alanine

Amino AA conc Cl2 Cons. DBP Formation (µg/mg-C) Acid (µM/mg-C)

(mg/mg-C) TOX THM TCAA DCAA HANs Unkn TOX

Glycine 0.030 0.0072 0.002 0.000 0.000 0.000 0.000 0.001 Alanine 0.030 0.0046 0.007 0.000 0.000 0.002 0.000 0.006 Valine 0.013 0.0022 0.009 0.002 0.001 0.002 0.000 0.005 Isoleucine 0.011 0.0018 0.004 0.000 0.000 0.002 0.000 0.001 Leucine 0.015 0.0022 0.000 0.000 0.000 0.002 0.000 -0.001 Serine 0.028 0.0083 0.001 0.000 0.000 0.000 0.000 0.001 Threonine 0.018 0.0068 0.012 0.000 0.000 0.000 0.000 0.011 Methionine 0.003 0.0010 0.004 0.001 0.000 0.001 0.000 0.003 Aspartic acid 0.026 0.0083 0.849 0.002 0.002 0.491 0.323 0.367 Glutamic acid 0.026 0.0036 0.004 0.000 0.002 0.002 0.000 0.001 Lysine 0.004 0.0013 0.001 0.000 0.000 0.001 0.000 0.000 Ornithine 0.005 0.0017 0.011 0.002 0.000 0.000 0.000 0.009 Arginine 0.019 0.0104 0.032 0.000 0.000 0.003 0.001 0.030 Histidine 0.007 0.0040 0.153 0.002 0.021 0.042 0.040 0.084 Asparagine 0.001 0.0004 0.012 0.000 0.000 0.005 0.000 0.009 Glutamine 0.001 0.0004 0.000 0.000 0.000 0.000 0.000 0.000 Tryptophan 0.006 0.0068 0.432 0.124 0.115 0.050 0.013 0.193 Phenylalanine 0.009 0.0017 0.000 0.000 0.000 0.003 0.001 -0.002 Tyrosine 0.006 0.0053 0.257 0.069 0.065 0.021 0.006 0.138 Total FAA 0.259 0.0780 1.789 0.201 0.207 0.626 0.385 0.856 Upper Limit 3.454 1.0403 23.855 2.677 2.765 8.340 5.131 11.418 Whole Waters 1.89 185 48.2 60 33.1 1.8 129.7 Total FAA 4.1% 1.0% 0.4% 0.3% 1.9% 21.4% 0.7% Upper Limit 55.0% 12.9% 5.6% 4.6% 25.2% 285.0% 8.8%

Analysis of Organic N-chloramines

Approach– Seems well suited to LC– Prior efforts with GC were not very successful

e.g., tosyl derivatization Proposal

– Fast analysis with UPLC– Parallel detection and analysis by

Post-column reaction with I and absorbance LC/MS/MS

Some New DBPs

Compound 50%ile 90%ile 99%ileN-Chloroiminoacetonitrile 0.3 0.6 2.5

N-N-Dichloroaminoacetonitrile 0.6 1.4 5.5

N-Chlorophenylacetaldimine 5.5 13 53

Concentrations in µg/L

Finished Drinking Water Concentrations